Pipe wrench



Aug. 13, 1946. A. M. RowLANb 2,405,757

v PIPE WRENCH Filed April 50, 1941 '7 She ets-Sheet 1 IN VEN TOR.

Aug. 13, 1946. A. M. ROWLAND PIPE WRENCH Filed April 50, 1941 INVENTOR.,aMlionL/mm- 7 Sheets-Sheet 2 Aug.13,1946; 4 A. M. Ram/L ND 2,405,757

PIPE WRENCH Filed April so, 1941 7 Sheets She t 3 0 P I H 1H p 3, '1 i!ML,

Arthur MRowlomd 1N VENTOR.

ATTORNEY.

Aug. 13, 1946. 'A. M. ROWLAND 'PIPE WRENCH 7 Sheets-Sheet 4 Filed April50,- 1941 A. 13, 194. A. M. ROWLAND I 2,405,157

' I I PIPE WRENCH Filed April 30, 1941 7 Sheets-Sheet 5 Qflrthur ILRowland 1N VENTOR 13; 1946 A. vM. ROWLAND 2,405,151

'PI PE WRENCH Filed April 30, 1941 7 Sheets-Sheet 6 Fig.1?

. Arthur INVENTOR.

B QIQJMM ATTORNEY.

g- 13, 1946- A. M. ROWLAND 2,405,757

PIPE WRENCH I Filed April 30, 1941 7 Sheets-Sheet 7 I firth UT;M.R0w]and INV ENT OR.

ATTORNEY.

Patented Aug. 13, 1946 PIPE WRENCH 7 Arthur M. Rowland, Graham, Tex.

Substituted for application Serial No. 161,713,

August 30, 1937.

1941, Serial No. 391,192

This invention relates to an improvement in pipe wrenches, and moreparticularly to wrench devices designed for rotating pipe joints forjoining together or disconnecting pipe sections, such as may be used inmaking up a pipe or in pulling the pipe from a well.

Heretofore, the screwing together and the unscrewing of pipe sections ofwell pipe, has in each instance been very laborious, usually beingaccomplished manually, or when provision is made for operating the sameby power, such devices have been so heavy and cumbersome as to be highlyobjectionable, expensive, and dimcult of transportation from place toplace where their use may be required.

It has been suggested that the rotary table of a rotary type drillingrig may be used to turn the lower portion of the drill pipe while theupper section is held stationary, to screw together or uncouple the pipesections. However, when the lower portion of the pipe is stuck in thewell, it is impossible to rotate it for disconnecting the pipe sections.Furthermore, it is frequently dangerous to rotate the portion of thedrill pipe that is in the well, especially when it is turned in adirection to unscrew it from other parts below the rotary table.

The object of this invention is to simplify and Claims. (Cl. 255-35)improve a. .device for screwing together or unscrewing pipe sections, toconstruct the same light in weight, capable of being transported easilyto the desired point of use, and. yet be so constructed as to beinexpensive, simple in construction and operation, but at the same timeprovide eifective means for coupling and uncoupling pipe sections.

In carrying out this object, I construct the device as a unit capable ofbeing supported either on an independent frame or suspended by a cable,and having provision for being applied to a drill pipe section ingripping engagement therewith substantially in the form of a rotarytable which has power driving means connected therewith capable ofturning the same to connect or disconnect the pipe sections.

I have shown different embodiments of the invention in the accompanyingdrawings, in which:

Fig. 115 a perspective view of one form of the machine, shown with thepipe or rod engaging unit open and in position where it may be moved toengage a pipe of a well;

Fig. 2 is a plan View of the pipe engaging unit, shown in engagementwith a pipe;

Fig. 3 is a similar view, showing the action of This application April30,

the internal mechanism of the engaging unit when the same is rotatedclockwise;

Fig. 4 is a plan view, partly in section, of one of the members of theunit that is adapted to contact the pipe;

Fig. 5 is a side elevation of the same;

Fig. 6 is a detail sectional view of a portion of the pipe engagingunit, illustrating the drive and rotatable support of the same;

Fig. 7 is a plan view of the machine;

Fig. 8 is a plan view of the pipe engaging unit, showing the same in anopen position and the springs omitted from one sector;

Fig. 9 is a plan view of the track for the unit;

Fig. 10 is an inverted plan view of the sectors of the pipe engagingunit, shown with the inner members omitted;

Fig. 11 is a detail sectional View of the drum operating means forpicking up pipe and other drilling units;

Fig. 12 is a detail side elevation of the frame structure showing manualmeans of control;

Fig. 13 is a side elevation of another form of the device as installedon a derrick;

Fig. 14 is a top plan view of the wrench device applied to a joint ofpipe, with parts broken away and in section; v

Fig. 15 is a detail side elevation showing the hinge construction of therotary table, taken substantially on the line l5l5 of Fig. 14;

Fig. 16 is a longitudinal sectional view through the wrench device;

Fig. 17 is a partial top plan view thereof wit the rotary table sectionsopen and the segments of one section removed;

Fig. 18 is a detail side elevation of the latch structure for the rotarytable, taken substantially on the line l8lll of Fig. 17, with thesections partly open;

Fig. 19 is a detail plan view of the base plate structure, showing thetorsion indicating device;

Fig. 20 is a detail bottom plan view thereof; and

Fig. 21 is a detached perspective view of a pipe gripping segment.

Different embodiments of the invention are shown respectively in Figs. 1to 12, and 13 to 21,

of which, that shown in Figs. 1 to 12 corresponds with the disclosure ofmy prior application Ser. No. 161,713, filed August 30, 1937, for whichthis application is substituted.

This mechanism, according to the form shown in Figs. 1 to 12, includes amotor I which is mounted on a frame. 2 and adapted to rotate a unitwhich is adapted to have frictional engage- 3 ment with the outerperiphery of a pipe, rod, or other element, especially those used in thedrilling and servicing of wells.

The pipe engaging unit consists of a rotary table or collar 3 which isformed in semi-circular units or sections that are hinged together bymeans of a hinge 4 and adapted to form a collar around a pipe. One ofthe faces of this gollar 3 is formed with integral concentric V-shapedextensions 6 and I which are adapted to fit into a sector of a track 5.The object of these extensions 6 and i and the track is to support andjournal the collar 3 so that it may be rotated by the motor I.Intermediate these V-shaped extensions B and I is a relatively widegroove which is cut with gear teeth 8, that are adapted to be meshedwith and driven by a pinion 9.

The pinion 9 is journaled in the body of the rack 5 and adapted to bedriven by the motor i. The pinion 9 is keyed or otherwise secured to anaxle or drive shaft it which is in operative connection with thetransmission H of the motor. A universal joint 12 is provided in theaxle it so that the track 5 and its pinion B may have a universalmovement relative to the motor I and its immediate frame. 7

The inner periphery of the collar 3 is adapted to carry loosely mountedsectors or segments l3 which are adapted to engage the outer peripheryof the object to be handled by the mechanism. These sectors i3 are somounted in the inner periphery of the collar 3, that when the collar 3is rotated in either direction while the object tends to hold thesectors stationary, they will be wedged against the object they engage.This movement of the sectors l3 relative to the body of collar 3 isattained by forming the inner periphery of the collar member 3 with aplurality of cam shaped grooves 14 and projections 15 which are adaptedto engage and cooperate with a plurality of projections and grooves l6and II, respectively, of the sectors l3, which projections have arcuateinner edges and coact with the arcuate inner edges of the grooves toprovide cam actions therebetween upon relative rotation of the parts.The outer peripheries of the sectors 13 are grooved to receive theprojections 15 of the collar member 3, and provided with xtensions 01cam shaped projections which are adapted to project into the internalgrooves M or the collar member 3. The grooves and extensions of themembers 3 and I3 serve to hold the sectors E3 in concentric relationwith the collar 3 and also to vary the radial movement of the sectors 13relative to the member 3.

4 sectors 13 is accomplished by means of springs which hold each sectorin an approximate central position within the inner arcuate opening ofthe member 3, that is, the ends of each sector 13 are in approximatealignment with the ends of its respective unit 3.

The face of each sector i3 is provided with a bolt or pin 20, which ispositioned midway between the ends of the sector, and this bolt servesto anchor the ends of two coil springs 21, and

' is also adapted to pass through the end of a bar In this instance, asector I3 is operatively car- 7 ried in each of the two sections of themember 3 and these two sectors are provided with toothed inserts 18which contact with the outer periphery of a pipe to be handled. When thesectors are provided with the inserts l8, these inserts may be removedand interchanged with sectors of difierent sizes to adapt the device topipe of various diameters.

It is desirable that each sector i3 have sufficient freedom of movement,relative to the member 3, so that the member 3 may be forced in itsrotation, with sudden jerks against the inertia of the pipe, in order tobreakthe threads loose and permit unscrewing of tight pipes. This ismore readily accomplished by providing means for balancing orresiliently holding the members l3 so that they may receive the'iulleffect of the cam action, each time the member is jerked rotatablyagainst the pipe. The balancing of the 22. The bar 22 extends radiallyfrom the sector I3, and is adapted to have a loose connection with theface of the member 3, so that it will not affect the movement of thesector l3, caused by the cam members it to H inclusive. The other endsof the coil springs 2| are secured to the face of the member 3, oneadjacent one end of the semi-circular portion of the member 3, and theother adjacent the other end of the same. The tension of these springs2| holds each sector I3, so that its ends will be in radial alignmentwith the ends of the corresponding section of the member 3.

When the member 3 is started in its rotation by the motor I, the tensionof the sectors 13, and their inserts [8 against the pipe, will ermit themember 3 to move a slight portion of its rotation before the cam actiontakes effect, against the tension of the springs 21, and moves thesectors l3 and the pipe that it engages. The extent of cam action willbe governed to a certain extent by the amount of rotatable resistancethat is ofiered by the pipe engaged.

In order for the sectors 13, and their inserts l8, to have tension atall times against the P pe engaged, a plunger 23 is operativelyositioned in the outer periphery of each sector l3, and adapted to havetension against the inner periphery of the member 3. This plunger 23 isinserted into an opening in the sector l3, so that it will bear againsta spring 24, which tends to push the plunger against the inner peripheryof the member 3, and holds the inserts l8 with sufficient tensionagainst the pipe to be handled.

An advantage of the springs 2i is that: when I all rotatable tension isremoved from the pipe engaged by the sectors 13, the sectors will moveto a position where they will oifer a minimum resistance in opening thecollar and releasing the pipe. The member 3, which is formed similar to.a collar, is cut in two equal sectors which are pivotally connectedtogether at 4. When these two sectors are closed so that they encompassa pipe, they are locked in such a manner as to permit the motor I torotate them in either direction. This locking means may be of anydesirable form, but is shown in this form of the invention, of a springform, which is positive and which will not release when it is movedwithin the field of the collar supporting member 5.

A desirable manner of using this type of pipe or rod engaging collar 3,is to provide a flexible means for driving the same so that it may havethe least amount of pressure and resistance to a pipe when the pipe isbeing threaded into a' coupling. The motor installation, as shown,permits the operator to control the collar 3, in speed and direction oftravel, throughout its universal movements. It is apparent that thmotive ower may be remote from the machine proper and the collar 3, maybe actuated and controlledas a separate unit,' but in order t have acompact and complete portable unit, it is'preferable to support themotor and to journal the collar track 5 in a cradle or frame 25, whichis adapted to reciprocate and to swing on the main frame 2. The frame25, consists of two parallel side members or channel irons which arepositioned longitudinally of the axis of the motor. The ends of thetrack member 5 are formed so that they extend into the ends of thesechannel irons and be held therein in a loose manner. A bolt 26 projectsin the form of studs from the opposite ends of the track member 5, whichstuds are loosely mounted in the frame 25 and pivotally sup-port thetrack 5 therein. A coil spring 2'! may be interposed between each end ofthe member 5, and the inner wall of the channel member of the frame 25,so as to permit the track 5, and its collar 3 to have sufficient play ormovement to accommodate the load or job. i

A second channel iron frame member 23 is positioned parallel with andaround the channel irons of the frame 25. The frame members 25,

may swing the motor and its track 5 on the piv otal connections 30 bymovement of the handle to form a bearing for the drum member 32. Thisare each provided with a plurality of rollers 26' which are adapted toroll in the channels 28. This arrangement permits the motor I, torecip-' rocate relative to the pipe to be handled, permitting the motorand its collar 3, to be moved to or from the pipe. The member 28, arepivotally connected to the horizontal frame members 29, of the mainframe 2, by pivotal connections 30. This arrangement permits theoperator of the device to adjust the positions of the motor and itscollar 3 simultaneously and to reciprocate the same in the frame 2, thusgiving universal action to the pipe engaging unit 3, and its motivepower.

The end of the crank shaft of the motor I, opposite the transmission maybe provided with an idler 3|, which is adapted to have frictionalengagement with and drive a drum 32 (Fig. 11). This drum 32 is movablyjournaled in the frame 25, and adapted to b actuated either to engagethe idler or drive wheel 3|, or to be moved into contact with a fixedbrake band 33, which is also supported on the frame 25. This drum 32 maybe used for picking up joints or other units that are being handled bythe collar 3.

The advantage of the universal movement of the engaging unit 3, is thatit will travel with the object that it engages during rotation of thesame. This permits use of the mechanism for rotary drilling, pumping,plugging wells without rigs, and various other uses. this engaging unitpermits its cooperating parts to function in the desired manner whenturned to any angle.

Figs. 1 and 12 illustrate the manual means for control of the positionof the motor I, the track 5, and cooperating parts. The frame 2 of thedevice is provided with integral upright members 41, which support theframe 29, and the frame 29 pivotally supports the track 28 for the motorframe 25. A rod 44 is positioned horizontally on the machine so that itwill have bearings on the upright frame members 41. The rod 44 is bentat one end to form a handle 45. The ends of the track members 28 areprojected to form bearings 40, for a horizontally disposed shaft4I. Theends of the shaft 4| are bent to form arms 42, that project through theouter ends of arms 43, and these arms 43 are each anchored at theirinner ends to the horizontally disposed rod 44. A coil spring 46 isattached to the rod 4|, and to a lower horizontal frame member 48 of theframe 2, so that normally it will hold resiliently the motor I and itscooperating parts in an approximately horizontal position. The operatorThe structure of,

arm 35 is extended above the drum 32, and pivotally connected to ahandle 31, by means of a link bar 38. One end of the handle 31 ispivotally connected with a bracket which is attached to the other motorframe member 25, by means of a pivot 39. Swinging of the handle 31 inone direction will move the member 32 into driving relation with thewheel 3|, and in the other direction, into contact with a brake member33, which is also carried on the frame of the motor I.

The open sector of the member 3, in Fig. 8, which is shown without thesprings 2|, more clearly illustrates the structure of the cam positionof the adjacent edges of the sector I3 and the inner periphery of thecollar 3. When the sector I3 is in normal relation to the collar portion3, its projections or cam members I6 project into the openings orgrooves I4 of the collar; and the grooves I! of the sector I3 receivethe projections l5 of the collar member 3. It is apparent that when thecollar member 3 is rotated a slight distance at the same time the sectorI3 is held against rotation, that the members M to I! inclusive willfunction to cause the sectors to move towards the center of the collar.This action takes place when the collar 3 is rotated in eitherdirection. Each groove I! of the sectors I3 is provided with an upperand a lower extension I1 which encases the projections I5 of the collarsectors 3 and serves to hold the sectors I3 in the plane of the collarand substantially concentric therewith.

The plan view of the track 5 (Fig. 9), illustrates the relation of thedrive pinion 9 thereto. This pinion is positioned so that it willproject through an opening that is provided in the member 5 between thetwo tracks 6 and I and into engagement with the teeth 8 of the collar 3.

Referring now to the form of the invention shown in Figs. 13 to 21,inclusive, this is illustrated as applied to joints of pipe, designatedgenerally at P, each having a collar P at one end to receive a coactingthreaded end of a connected pipe section. The lower pipe sections in thewell may be grasped by a conventional holding spider H, while thecoupled pipe section P is supported by an elevator E engaging just belowthev collar P and suspended by a swivel S carried in the usual Way inthe derrick D. These parts support the pipe section P to be coupled withor uncoupled from the pipe section in the well by the wrench deviceconstituting this form of the invention.

This wrench device is constructed of a base frame 5| having laterallyprojecting lug 52 on opposite sides thereof receiving therein upwardlyextending rods 53, while a coacting rod 54 is joined to the opposite endof the base frame 5|, and is coupled therewith by a ring 55. The rods 53and 54 thus form a triangular suspending frame for the wrench device forholding the same in proper position for operation. This triangularsupporting frame is suspended from the lower end of a cable .56 attachedto the ring 55 at one end and having its opposite end attached to an arm51- pivoted at 58 to the derrick D with a weight 59 connected with theopposite end of said arm sufficiently heavy to counterbalance the weightof the wrench device.

The base plate 5| has one end thereof formed of substantially arcuateshape, and about which extends a segmental track 89. This track 60 isconstructed of T-shape and is secured on the base plate 5| by screws 6|,to support the rotary table on the base plate for turning movementrelative thereto, as shown in Figs. 16 and 19.

The rotary table is constructed of semi-circular sections, designatedgenerally by the numeral 62, which have a groove 53 in the under sidethereof receiving and riding on the track 69 to hold the rotary table inplace on the base plate 5!, but when turned to proper relation thereto,one of the sections 62 may be swung to an open position, as shown inFig. 17, while the other section remains on the segmental track 60.

The periphery of the sectional rotary table 52 is formed .with gearteeth 64 adapted to mesh with a pinion 65 mounted on a stub shaft to.The stub shaft 65 is journaled in bearings 6'! in the base plate 5| andextends into a gear housing 68 where it has mounted thereon an enlargedbevel gear 69. The gear 69 is in mesh with a beveled pinion l fixed on adrive shaft H eXtending from the housing 68 lengthwise of the base plateand having universal joints 12 therein (Fig. 13) to accommodate forfreedom of swinging movement of the wrench device to diiferent positionsrelative to the derrick D. The drive shaft 7! is driven by a power unitmounted on the derrick D, said power unit comprising gearing I3 mountedon the derrick and connected by a sprocket chain 14 with a drum I5,which in turn is driven from a suitable source of power by a sprocketchain I6. This mechanism provides for the rotary turning movement of thesectional table 62 in either direction, as may be desired for couplingor disconnecting the pipe joints.

The pinion 65 is enclosed within a gear cover 1'? to protect the handsof the workmen from the same and to prevent the mashing thereof betweensaid pinion and the gear teeth 64. Guards E8 preferably of rubber orother resilient material are provided also on opposite sides of thepinion 65 to prevent the hands of workmen from becoming entangledbetween the gear teeth and pinion, and as a Warning thereof beforebecoming engaged therebetween. The gear 64 is rotated very slowly sothat this warning will be sufficient to enable the operator to removehis hand upon engagement with either of the guards 18.

While the table sections 62 are constructed semi-circular, they may beconnected in annular form, for which purpose they are hinged together atone side and have a latch device at the opposite side thereof. The hingeis designated genally at 19 and has the axis thereof slightly offsetfrom the center line of the table sections, as shown in Figs. 14 and 15.to facilitate the relative separation of the sections, as shown in Fig.17, enabling one section to be swung away from the other when turned tothe position shown. The sections are adapted to be secured in closedrelation by a latch member 88 of substantially T- shape arranged toengage over lugs 8| on one of the sections, while the latch is journaledon an eccentric 82 fixed on a shaft 82; and said latch member 80 has anoffset projection 83 extending laterally in the path of a lever 84,secured to the shaft 82. Thus, when the lever 84 is turned to theposition shown in'Figs. 17 and 18, it bears down on the projection 83and lifts the latch out of engagement with the lugs 81, but allows thelatch to engage over the lugs when the lever 84 is swung to its oppositeposition, as shown in Fig. 14.

' To provide for proper alignment of the sections, the opposite ends ofthe respective sections are formed with complementary interengagingrecesses 86 and tongues 81, as shown in Figs. 14, 17 and 18.

.Each of the rotary table sections 62, has a gripping segment 88 mountedtherein and carrying a toothed pipe gripping element 89, as shown inFig. 14. Each of the segments 88 is constructed substantially as shownin Fig. 21 with peripheral notches 90 and 9| arranged in staggeredrelation and alternating with arcuate edge portions 92. Thecorresponding table section 62 has projections 93 and 94 formed on theinner surface thereof in staggered relation and having arcuate inneredges to interfit respectively with the notches 9i and 90 of the segment88, the arcuate portions 82 on the segment fitting within grooves 95between the projections 94 of the table section to provide cam actiontherebetween upon relative rotation of these parts.

The segments 88 fit loosely in the table sections -32, but are urgedinward by pins 96 slidably mounted in the sides of the table sections inalignment with the grooves 95, and pressed inward by a leaf spring Ellhaving its opposite ends bearing against the pins 93 and secured at 98intermediate its ends to a side of the section 62, as by a bolt orscrew. The inward movement of the segments 83 is limited by retainingmembers 99, the outer ends of which are hooked over peripheral portionsof the table sections, while the inner ends are secured to the segmentsby bolts or screws Hill which are readily removable to permit thesegments to be taken out or reversed as desired, This is desirable whenthe pipe is to berotated in a reverse direction requiring the reversalof the segments 88 to provide the proper gripping action on the pipe.

In using this device, it is adapted to be suspencled in a horizontalposition substantially as shown in Fig. 13, in which position it iscapable of movement laterally for proper gripping action around the pipejoint P. The table sections 62 may be opened, as shown in Fig. 17, toembrace the pipe joint, and. then looked in place therearound by theclosing of the latch 89, as shown in Fig. 14. The height of the unitshould be adjusted so as to obtain the proper gripping action on thepipe joint which may be varied by raising or lowering the cable 56, fromwhich the bars 53 and 54 are suspended,

When thus applied to the pipe joint in proper gripping relation thereto,the power mechanism is operated to drive the bevel gearing 69'|l andthus rotate the gearing 64-455, turning the r0- tary table 62. Althoughthe segments 88 are pressed inward by the springs 91 with the grippingelements 89 engaging the pipe joint P, this inward pressing action isincreased by the turning movement of the table 52 which tends to have arelative movement to the segments 88, thereby shiiting the flangeportions 93-94 relative to the grooves or notches Qfl-Sl in thesegments, substantially in cam action, thereby forcing the segments intotighter gripping engagement with the pipe joint sufliciently to rotatethe joint with the turning movement of the table, as indicated by thearrow in Fig. 14. By reversing the positions of the segments 88 relativeto the sectional table, the pipe joint may be turned in the reversedirection for unscrewing from the pipe in the well.

The unit is held against lateral shifting movement during the rotationof the table by cables secured to opposite sides thereof and anchored atdesired positions in the derrick D. At one side, the base frame 5| has2. lug I| attached thereto, as shown in Fig. 14, to which one anchoringcable is adapted to be secured. The opposite side of the base has 3. lugHi2 connected with the base 5| by pins I93 extending through slots I04in the lug for limited sliding movement thereof relative to the base. Acable is shown at "35 connected by a hook N16 to this lug I02, saidcable extending laterally to a portion of the derrick to which it isanchored. This slidable movement of the lug m2 makes it possible todetermine the degree of torsion applied to the pipe, for which purposethe lug I02 is pivotally connected at I81 with one end of a pointer armI08 (Figs. 14 and which pointer arm has a slot I09 therein providing aslidable pivotal connection for the pointer on a pin I I0 secured to thetable 5!. The pointer arm I08 extends through a slot l l I in .the base5! and coacts with a graduated scale or indications H2 to indicate theextent of torsion applied to the pipe. This is made possible by thepivot pin Nil extending through a lot H3 in the base 5| with a leafspring H5 bearing thereagainst in opposed relation to the pull appliedto the cable H35. When the pipe is being screwed together, the powerapplied to the sectional table 62 will tend to cause a lateral movementof the base frame 5| according to the degree of torsion applied to thepipe, which in turn, will move the pivot pin H11 in the slot H3, causinga turning movement of the lever arm I68 about the pin Hi to a degreecorresponding with the torsion applied to the pipe, thereby indicatingat I I2 the extent of turning moment of the pipe.

I claim:

1. Mechanism for handling pipe, and thelike, comprising a split collarhaving sections hinged together with means for holding the same inclosed concentric relation, each of said sections carrying a segmentmounted therein having means for gripping engagement with a pipe, meansforming a plurality of interfitting cam surfaces between each collarsection and its segment arranged to force the segment inward in grippingengagement with the pipe upon relative turning movement of the collar ineither direction with respect to the segments, said cam means includinga plurality of circumferentially aligned grooves and ribs on thesegments, and interfitting grooves and ribs on the collar and arrangedin cooperating overlapping relation with each other, and means forrotating the collar in either direction.

2. Mechanism for handling pipe, and the like, comprising a split collarhaving sections hinged together with means for holding the same inclosed concentric relation, each of said sections carrying a segmentmounted therein having means for gripping engagement with a pipe, meansforming a plurality of interfitting cam surfaces between each collarsection and its segment arranged to force the segment inward in grippingengagement with the pipe upon relative 1Q interfitting respectively witha rib and recess circumferentially aligned in the supporting collarsection thereof, and means for rotating said collar.

3. In pipe turning mechanism, a collar adapted to surround a pipe, asegment mounted therein and. having means for gripping engagement 'Witha pipe, and means forming a plurality of interfitting cam surfacesbetween said collar and the segment arranged to force the segment inwardupon relative turning movement thereof, said cam means including acircumferentially aligned groove and rib on the segment and aninterfitting rib and groove on the collar.

4. In pipe turning mechanism, a collar adapted to surround a pipe, asegment mounted therein and having means for gripping engagement with apipe, and means forming a plurality of interfitting cam surfaces betweenaid collar and the segment arranged to force the segment inward uponrelative turning movement thereof, said cam means including a pluralityof circumferentially aligned grooves and ribs on the segment andinterfitting ribs and grooves on the collar arranged in cooperatingoverlapping relation with each other. T

5. In pipe turning mechanism, a support, an annular collar forsurrounding and engaging a pipe to rotate the same, said collar having aside only thereof arranged. in horizontal overlapping relation with saidsupport and having the major portion thereof projecting free from saidsupport, and means connected between the overlapping portions of thecollar and the support for journaling said collar on the supportincluding a substantially T-shaped track connected with one of saidelements and a portion connected with the other of said elements andhaving a groove therein embracing opposite sides of the head portion ofthe T-shaped track.

6.,In pipe turning mechanism, a support, -an annular collar forsurrounding and engaging a pipe to rotate the same, said collar having aside only thereof arranged in horizontal overlapping relation with saidsupport and having the major portion thereof projecting free from saidsupport, and means connected between the overlapping portions of thecollar and the support for journaling said collar on the supportincluding a substantially T-shaped track connected with one of saidelements and a portion connected with the other of said elements andhaving a groove therein embracing opposite sides of the head portion ofthe T-shaped track, said collar including segmental sections adapted tobe opened to receive the pipe, and the track being arcuateand of shortercircumferential length than one of the sections and suporting the collarthereby when opened.

7. In pipe turning mechanism, a collar adapted to surround. a pipe andincluding an arcuate section, a complementary segment mounted in thesection and having means for gripping engagement with a pipe, saidsection and segment having facing sides with normally opposed curvedsurfaces approximately concentric with said collar, one of said membershaving grooves in said facing side thereof curved at the inner edgethereof on a different radius from said curved surfaces, and the otherof said members having ribs thereon normally interfitting with saidgrooves, said interfitting ribs and grooves being spaced apartcircumferentially for inward movement of the segment upon turningmovement of the collar.

8. In pipe turning mechanism, a collar adapted to surround a pipe andincludin an arcuate section, a complementary segment mounted in thesection and having means for gripping engagement with a pipe, saidsection and segment having facing sides with normally opposed curvedsurfaces approximately concentric with said collar, one of said membershaving grooves in said facing side thereof curved at the inner edgethereof on a different radius from said curved surfaces, and the otherof said members having ribs thereon normally interfitting with saidgrooves, said interfitting ribs and grooves being spaced apartcircumferentially on opposite sides of the opposed curved surfaces ofsaid members for inward movement of the segment upon turning movement ofthe collar in either direction. 9. In pipe turning mechanism, a collaradapted to surround a pipe and including anarcuate section, acomplementary segment mounted in the section and having means forgripping engagement with a pipe, said section and segment having facingside with normally opposed curved surfaces approximately concentric withsaid 001-- lar, one of said members having grooves in said facing sidethereof curved at the inner edge thereof on a difierent radius from saidcurved sufaces, and the other of said members having ribs thereonnormally interfitting with said grooves, and havin the peripheral edgesthereof curved complementary to said grooves, said interfitting ribs andgrooves being spaced apart circumferentially on opposite sides of theopposed curved surfaces of said members for inward: movement of thesegment upon turning movement of the collar in either direction.

10; In pipe turning mechanism, a collar adapted to surround a pipe andincluding a section, means for supporting said collar for turningmovement, a segment within said section and having means for grippingengagement with a pipe, said section and segment being shaped ascomplementary arcuate members approximately concentric with said collarwith circumferentially spaced arcuate ribs'on opposite sides thereof,said member having an arcuate rib thereon vertically aligned withsaid'arcuate surface and of a different radius, and the other memberhaving circumferentially aligned arcuate grooves interfitting with theribs and complementary thereto and having arcuate surface complementaryto the arcuate surfaces of the first-mentioned member.

ARTHUR M. ROWLAND.

